(a) Field
The present disclosure relates to a fiber-reinforced plastic vehicle body structure.
(b) Description of the Related Art
Conventionally, steel is used to manufacture the structural components of a vehicle's body. In recent years, however, fiber-reinforced plastic (FRP) or carbon fiber-reinforced plastic (CFRP) is being used instead for vehicle body structures, which reflects the modern trend toward more lightweight vehicles that have improved fuel consumption.
In the manufacture of a vehicle body structure using the fiber-reinforced plastic or carbon fiber-reinforced plastic, the vehicle body structure is molded by preparing a foam core of a predetermined shape, wrapping prepreg fibers around the foam core, inserting the wrapped foam core into a mold, and then, applying heat and pressure to the mold.
After molding a lightweight plastic vehicle body structure as stated above, each part constituting a vehicle body is connected to other vehicle body structures, thereby forming the vehicle body.
FIG. 1 shows an example of when configuring part of a vehicle body by connecting a second vehicle body structure 20 having a plurality of barrier ribs 22 to a first vehicle body structure 10 having an approximately π-shaped channel, a connecting flange 24 extending in width is formed at the tip end of the second vehicle body structure 20.
Next, an adhesive 26 is applied to the connecting flange 24 to bond the connecting flange 24 and the first vehicle body structure 10 together. Also, in order to strengthen the bond, a screw or bolt is fastened to the connecting flange 24 to interconnect the first vehicle body structure 10 and the second vehicle body structure 20.
When a vehicle body is configured by connecting two vehicle body structures 10 and 20, as shown in FIG. 1, by bonding them with an adhesive and mechanically fastening them, the carbon fiber that connects the two vehicle body structures 10 and 20 is discontinuous, thus deteriorating the physical properties and strength of the connecting portions.
Moreover, there is a risk that the connecting portions might be damaged or broken due to stress caused by external loads, and the resulting degradation in their strength. Besides, resistance to collision or impact may be degraded since load weight may not be properly distributed between the first vehicle body structure 10 and the second vehicle body structure 20. Furthermore, a decrease in productivity or increase in production costs may result, due to having to undertake an additional process for interconnecting the first and second vehicle body structures 10 and 20.